The present invention generally relates to control valves, and more particularly, relates to a variable pressure fluid control valve that includes a quick exhaust control feature selectively actuated in response to the regulated output of a proportional regulator.
Control valves having a pressure regulator are often used to exhaust excess fluid pressure. Traditionally, these pressure regulators act to relieve fluid pressure by exhausting the fluid through a fluid passage within the pressure regulator assembly. However, often fluid relief passages are relatively small and require an extensive amount of time to exhaust the fluid pressure. Accordingly, these known pressure regulators may not maximize the fluid exhaust rate of the control valve.
Control valves often employ pressure regulators to maintain a predetermined fluid pressure in response to a control signal. However, control valves in general are not particularly suited to operate as pressure regulators, since they are unable to rapidly adjust to a higher pressure and rapidly adjust to a lower pressure. Specifically, these control valve may be capable of rapidly increasing pressure, however they are notoriously slow at reducing pressure. Hence, they may not supply sufficient control of the fluid pressure under all operating parameters.
Accordingly, there exists a need in the relevant art to provide a control valve capable of providing variable fluid regulation while simultaneously capable of providing rapid fluid pressure exhaust. Furthermore, there exists a need in the relevant art to provide a single control valve capable of providing variable fluid regulation and rapid fluid pressure exhaust in response to a simple pilot pressure. Still further, there is a need in the relevant art to provide a control valve capable of overcoming the disadvantages of the prior art.
A control valve system having an advantageous construction is provided. The control valve system including a housing defining an inlet, an outlet, and an exhaust. A first passage extends between the inlet and the outlet and a second passage extends between the outlet and the exhaust. The control valve system includes a first valve disposed within the first passage. The first valve is movable between a closed position and an opened position. Similarly, the control valve system includes a second valve disposed within the second passage. The second valve is movable between a closed position and an opened position. Furthermore, the control valve system includes a regulator circuit operably coupled to the housing, which outputs a pilot pressure in response to an input signal. An actuating member is slidably disposed within the housing and moveable in response to a pressure differential between the outlet and the pilot pressure. The actuating member independently actuates the first valve or the second valve to provide a quick pressure or exhaust feature.
The control valve system of the present invention possesses the ability to rapidly respond to a pilot pressure and, consequently, rapidly change the output fluid pressure to a higher or lower pressure in response to a pilot pressure signal while providing fluid flow to a cylinder or device. The control valve system of the present invention can start at any fluid pressure in its range, including zero pressure, and rapidly adjust to any other pressure within its range. It is unique in its ability to change its pressure higher or lower quickly while simultaneously providing fluid flow.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.